com.opensearchserver.extractor.parser.PdfBox.java Source code

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Here is the source code for com.opensearchserver.extractor.parser.PdfBox.java

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/**
 * Copyright 2014-2015 OpenSearchServer Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.opensearchserver.extractor.parser;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import java.util.Calendar;
import java.util.Date;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDDocumentCatalog;
import org.apache.pdfbox.pdmodel.PDDocumentInformation;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.encryption.StandardDecryptionMaterial;
import org.apache.pdfbox.util.PDFTextStripper;

import com.opensearchserver.extractor.ParserAbstract;
import com.opensearchserver.extractor.ParserDocument;
import com.opensearchserver.extractor.ParserField;

public class PdfBox extends ParserAbstract {

    public static final String[] DEFAULT_MIMETYPES = { "application/pdf" };

    public static final String[] DEFAULT_EXTENSIONS = { "pdf" };

    final protected static ParserField TITLE = ParserField.newString("title", "The title of the Word document");

    final protected static ParserField AUTHOR = ParserField.newString("author", "The name of the author");

    final protected static ParserField SUBJECT = ParserField.newString("subject", "The subject of the document");

    final protected static ParserField CONTENT = ParserField.newString("content", "The content of the document");

    final protected static ParserField PRODUCER = ParserField.newString("producer", "The producer of the document");

    final protected static ParserField KEYWORDS = ParserField.newString("keywords", "The keywords of the document");

    final protected static ParserField CREATION_DATE = ParserField.newDate("creation_date", null);

    final protected static ParserField MODIFICATION_DATE = ParserField.newDate("modification_date", null);

    final protected static ParserField LANGUAGE = ParserField.newString("language", null);

    final protected static ParserField ROTATION = ParserField.newInteger("rotation", null);

    final protected static ParserField NUMBER_OF_PAGES = ParserField.newInteger("number_of_pages", null);

    final protected static ParserField CHARACTER_COUNT = ParserField.newInteger("character_count", null);

    final protected static ParserField LANG_DETECTION = ParserField.newString("lang_detection",
            "Detection of the language");

    final protected static ParserField[] FIELDS = { TITLE, AUTHOR, SUBJECT, CONTENT, PRODUCER, KEYWORDS,
            CREATION_DATE, MODIFICATION_DATE, LANGUAGE, ROTATION, NUMBER_OF_PAGES, LANG_DETECTION };

    public PdfBox() {
    }

    private Calendar getCreationDate(PDDocumentInformation pdfInfo) {
        try {
            return pdfInfo.getCreationDate();
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    private Calendar getModificationDate(PDDocumentInformation pdfInfo) {
        try {
            return pdfInfo.getCreationDate();
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    private Date getDate(Calendar cal) {
        if (cal == null)
            return null;
        return cal.getTime();
    }

    private void extractMetaData(PDDocument pdf) throws IOException {
        PDDocumentInformation info = pdf.getDocumentInformation();
        if (info != null) {
            metas.add(TITLE, info.getTitle());
            metas.add(SUBJECT, info.getSubject());
            metas.add(AUTHOR, info.getAuthor());
            metas.add(PRODUCER, info.getProducer());
            metas.add(KEYWORDS, info.getKeywords());
            metas.add(CREATION_DATE, getDate(getCreationDate(info)));
            metas.add(MODIFICATION_DATE, getModificationDate(info));
        }
        int pages = pdf.getNumberOfPages();
        metas.add(NUMBER_OF_PAGES, pages);
        PDDocumentCatalog catalog = pdf.getDocumentCatalog();
        if (catalog != null)
            metas.add(LANGUAGE, catalog.getLanguage());
    }

    /**
     * Extract text content using PDFBox
     * 
     * @param pdf
     * @throws Exception
     */
    private void parseContent(PDDocument pdf) throws Exception {
        try {
            if (pdf.isEncrypted())
                pdf.openProtection(new StandardDecryptionMaterial(""));
            extractMetaData(pdf);
            Stripper stripper = new Stripper();
            stripper.getText(pdf);
        } finally {
            if (pdf != null)
                pdf.close();
        }
    }

    @Override
    public void parseContent(InputStream inputStream, String extension, String mimeType) throws Exception {
        parseContent(PDDocument.loadNonSeq(inputStream, null));
    }

    @Override
    public void parseContent(File file, String extension, String mimeType) throws Exception {
        parseContent(PDDocument.loadNonSeq(file, null));
    }

    @Override
    protected ParserField[] getParameters() {
        return null;
    }

    @Override
    protected ParserField[] getFields() {
        return FIELDS;
    }

    @Override
    protected String[] getDefaultExtensions() {
        return DEFAULT_EXTENSIONS;
    }

    @Override
    protected String[] getDefaultMimeTypes() {
        return DEFAULT_MIMETYPES;
    }

    public class Stripper extends PDFTextStripper {

        public Stripper() throws IOException {
            super();
        }

        @Override
        protected void endPage(PDPage page) throws IOException {
            super.endPage(page);
            ParserDocument document = getNewParserDocument();
            String text = output.toString();
            document.add(CHARACTER_COUNT, text.length());
            document.add(CONTENT, text);
            document.add(LANG_DETECTION, languageDetection(CONTENT, 10000));
            document.add(ROTATION, page.findRotation());
            output = new StringWriter();
        }
    }
}